Browsing by Title

Sort by: Order: Results:

  • A butterfly diagram and carrington maps for century-long Ca II K spectroheliograms from the Kodaikanal Observatory 
    Chatterjee, Subhamoy; Banerjee, D; Ravindra, B (IOP Publishing, 2016-08-10)
    The century-long (1907–2007) Ca II K spectroheliograms from the Kodaikanal Solar Observatory (KSO) are calibrated, processed, and analyzed to follow the evolution of the bright on-disc structures called plages, possible ...
  • BV photometry and H-alpha spectroscopy of the RS Canum Venaticorum binary V711 Tauri 
    Mohin, S; Raveendran, A. V (European Southern Observatory, 1993-08)
    Differential BV photometry of V711 Tau obtained on a total of 120 nights during the years 1984-1991 and H-alpha spectroscopy obtained on 14 nights during the 1990-1991 observing season are presented. We find that the mean ...
  • BV photometry and Hα spectroscopy of the RS Canum Venaticorum binary UX Arietis. 
    Raveendran, A. V; Mohin, S (EDP Sciences, 1995-09)
    We present differential BV photometry of UX Ari obtained on 76 nights during 1989-94 and Hα spectroscopy obtained on 14 nights during the 1990-91 observing season. The migration of the phase of light minimum indicates a ...
  • BV Photometry and Hα Spectroscopy of the Rs-Canum Binary II-Pegasi 
    Mohin, S; Raveendran, A. V (European Southern Observatory, 1993-09)
    Differential BV photometry of II Peg obtained on a total of 57 nights during the years 1986-1991 and Hα spectroscopy obtained on 12 nights during the 1990-1991 observing season are presented. From an analysis of the available ...
  • BV photometry of UX ARIETIS 
    Mohin, S; Raveendran, A. V (Indian Academy of Sciences, 1989-03)
    Differential BV photometry of UX Ari obtained on 58 nights during 1984-1985, 1985-1986, 1986-1987, and 1987-1988 observing season is presented. It is found that (B-V) is phase dependent, with the system being reddest at ...
  • BVR photometry of a newly identified RS CVn binary star HD 61396 
    Barway, Sudhanshu; Pandey, S. K; Parihar, P. S (Elsevier, 2004-12)
    BVR photometry of a recently identified RS CVn binary star HD 61396, carried out during 2001, is presented. The new photometry reveal significant evolution in the shape and amplitude of light curve when compared with those ...
  • BVRI CCD photometric standards in the field of GRB 990123 
    Nilakshi; Yadav, R. K. S; Mohan, V; Pandey, A. K; Sagar, R (Astronomical Society of India, 1999)
    The CCD magnitudes in Johnson BV and Cousins RI photometric passbands are determined for 18 stars in the field of GRB 990123. These mesurements can be used in carrying out precise CCD photometry of the optical transient ...
  • BVRI photometry of a few `unidentified' IRAS sources 
    Iyengar, K. V. K; Parthasarathy, M (EDP Sciences, 1997-01)
    We selected 33 unidentified IRAS sources based on the following criteria: i) galactic latitude more than 2 deg, ii) have flux density higher than 1 Jy at 12 microns, iii) have good fluxes at 12, 25, and 60 microns with ...
  • BVRI photometry of the Dipper Asterism region in M 67 
    Anupama, G. C; Kembhavi, A. K; Prabhu, T. P; Singh, K. P; Bhat, P. N (European Southern Observatory, 1995-02)
    We present Cousins BVRI magnitudes for stars in the M 67 `dipper asterism' region, based on observations carried out at the prime focus of the 2.3 m Vainu Bappu Telescope of the Vainu Bappu Observatory, Kavalur. The ...
  • BVRI polarimetry of carbon stars 
    Raveendran, A. V (European Southern Observatory, 1991-03)
    BVRI polarimetry of carbon stars belonging to different variability types - VX And, UU Aur, T Cae, Y CVn, U Hya, Y Hya, RY Mon, W Ori, Y Per, RT Pup, and X Vel - is presented. Though there is significant scatter, on the ...
  • BVRIJHK photometry of post-AGB candidates 
    Fujii, T; Nakada, Y; Parthasarathy, M (E D P Sciences, 2002-04)
    BVRIJHK photometric observations are presented for 27 post-AGB candidates. Almost all objects show a double peaked SED curve in the optical to far-infrared wavelengths. Seventeen objects were classified as post-AGB stars ...
  • BVRIJHK photometry of post-AGB candidates: evolution of post-AGB central stars 
    Fujii, T; Nakada, Y; Parthasarathy, M (Kluwer Academic Publishers, 2001-08)
    Post-AGB stars are generally believed to be on their way to the planetary nebula stage. However, there has been a question about the evolutionary path for the low-mass ones. We present BVRIJHK photometry of post-AGB ...
  • B’lore to Ladakh, in search of the sun: world’s largest solar telescope to Aid IIA team’s project In Merak 
    Times of India (Times of India, 2012-09-23)
  • C. Ragoonatha Charry and variable star astronomy 
    Kameswara Rao, N; Vagiswari, A; Thakur, P; Birdie, C (Centre for Astronomy, 2009-11)
    C. Ragoonatha Charry, the First Assistant at Madras Observatory from 1864 to 1880, was not only a noted Indian observational astronomer but also someone who emphasized the need for incorporating modern observationally-based ...
  • C1XS results—first measurement of enhanced sodium on the lunar surface 
    Athiray, P. S; Narendranath, S; Sreekumar, P; Grande, M (Elsevier B.V, 2014-12)
    We describe the first unambiguous evidence of enhanced sodium on the lunar surface revealed by the Chandrayaan-1 X-ray Spectrometer (C1XS). The C1XS onboard the Chandrayaan-1 spacecraft was designed to map the surface ...
  • CA II K bright points and the solar cycle 
    Sivaraman, K. R (Springer, 1984-09)
    We have made number counts of the bright points that populate the interior of the Ca II network in the solar chromosphere for four solar cycles. We find that the number of these fine structures during the solar maximum ...
  • Ca II K Emission from the Solar Chromosphere 
    Sivaraman, K. R (Indian Institute of Astrophysics, Bangalore, 1986)
    The role of the Ca II K line as a reliable diagnostic of the chromospheric activity on the Sun is reviewed. The chromospheric structures seen in this line serve as good indicators of the photospheric magnetic structures ...
  • Ca II K Emission in Canopus 
    Bappu, M. K. V; Mekkaden, M. V; Kameswara Rao, N (Astronomical Society of India, 1984-06)
    The Changes in the Ca II K line profile of the F0 supergiant Canopus have been studied from the high dispersion coude spectrograms obtained since 1975. The emission in the core of the line is variable in a timescale of few ...
  • CA II K Line Profile of the Truly Quiet Sun 
    Sivaraman, K. R; Gupta, S. S; Kariyappa, R (Kluwer Academic Publishers, 1996-01)
    While evaluating the chromospheric variability (solar cycle related or any other) using the Ca II K line (λ3933.684 Å) as an indicator, an essential prerequisite is the knowledge of the profile of a truly quiet Sun in the ...
  • CA II K2V spectral features and their relation to small-scale photospheric magnetic fields 
    Sivaraman, K. R; Livingston, W. C (D. Reidel Publishing Co.,, 1982-10)
    Although the Ca ii K232 network is known to be cospatial with magnetic elements there has been doubt as to the magnetic origin of the fainter K2V points. We demonstrate that weak magnetic elements also lie at the roots of ...

Search DSpace

Browse

My Account